The Shanghai Composite Index was up 2.4% at 3,199.56 by late morning after swinging between gains and losses.

Trading in Chinese stocks was suspended on Thursday after a key index plunged 7%.

China's stock markets have little connection to the rest of its economy but two sharp price declines this week have focused attention on the slowdown in the nation's growth.

Stocks worldwide and oil fell on concern about weaker Chinese demand. In the US, the Dow Jones industrial average sank 2.3% and the Standard & Poor's 500 lost 2.4% on Thursday. The Nasdaq composite index fell 3%.

European markets also fell. Germany's DAX slid 2.3%, France's CAC 40 gave up 1.7%, and Britain's FTSE 100 lost 2%.

"The poor start to the year clearly warns that global growth concerns remain, that commodity prices are still under downwards pressure and that volatility in investment markets will likely remain high," said strategist Shane Oliver of AMP Capital.

In other Asian markets, Tokyo's Nikkei 225 rose 0.4% to 17,848.10 while Sydney's S&P/ASX 200 was off 0.7% at 4,973.20.

Hong Kong's Hang Seng advanced 1.1% to 20,559.34 and Seoul's Kospi was little changed at 1,903.14. Stocks rose in Taiwan and were mixed in south-east Asia.

On Thursday, Chinese stock trading halted for the day after the CSI 300 plunged 7%, tripping a "circuit breaker" that is meant to dampen volatility.

Today, that benchmark gained 3% at the opening, then fell to a 4.3% loss before recovering.

Late on Thursday, Beijing suspended use of that "circuit breaker" after economists warned it was adding to volatility by encouraging investors to sell faster when the market falls.

The latest plunge in Chinese stocks was set off by concern Beijing is allowing its yuan to weaken too fast against the dollar.

The People's Bank of China has allowed the yuan to decline gradually since August after loosening its tie to the dollar.

The American currency has risen over the past year, leaving the yuan overvalued compared with other developing countries and hurting Chinese exporters.

On Thursday, the yuan's exchange rate was set at its lowest level since 2011, sparking fears further declines might lead to a capital outflow.

"We suspect this is poor communication by the People's Bank rather than a deliberate devaluation," said David Rees of Capital Economics.

Worries about China were fuelled by weaker-than-expected December manufacturing activity. Those fears have drowned out signs that the US and Europe are doing fairly well.